1. Field of the Invention
The present invention relates to an image forming apparatus such as an identification photograph producing apparatus. More specifically, the present invention relates to the image forming apparatus capable of executing proper calibration of an imaging device and a printing device.
2. Background Arts
An identification photograph producing apparatus is well-known, in which an identification photograph for a driver""s license and a passport is easily produced by putting a charge and making simple commands. In the identification photograph producing apparatus are provided a photographing room and a photo making chamber, which are parted by a partition wall. In the photographing room, there are a chair for sitting, lighting equipments, console panel and so forth. The photo making chamber has an image forming apparatus, wherein an imaging device and a printing device are incorporated.
In general, when imaging and printing characteristics of the image forming apparatus are varied, image quality of a print image is also varied. For instance, imaging characteristics of an electric still camera, used as the imaging device, are deviated by age-based deviation in an imaging element like a CCD image sensor, and by age-based deviation in the lighting equipments. Moreover, in the printing device, density characteristics of a print image are varied by deviation in recording sheets and print conditions (temperature, humidity and so forth). In order to keep image quality of the print image regardless of these age-based deviations and deviation in print and lighting conditions, it is needed to perform calibration of image forming apparatus in certain intervals, in each repair or parts exchange, and each supplement of recording sheets.
Japanese Laid-open Patent Publication (JP-A) No. 06-233179 discloses a photographing device in which diaphragm correction and color balance adjustment are executed in a period of absence of a person at a photographing position. Moreover, JP-A No. 10-063047 discloses an image forming device to monitor temperature, print number, toner amount and so forth, and to output a calibration request to a user when detecting age-based deviation, variation in temperature and so forth.
In the above devices, however, only the imaging device or the printing device is calibrated. Thus, when characteristics of the imaging device and the printing device are varied, it is not possible to have effective calibration.
In view of the foregoing, an object of the present invention is to provide an image forming apparatus to execute effective calibration by adjusting characteristics of both the imaging device and the printing device.
To achieve the above objects, an image forming apparatus of the present invention is comprised of photographing means for photographing a subject and outputting image data of a subject image, printing means for printing the subject image on the basis image data from photographing means, a first test chart used in calibration of photographing means, a second test chart used in calibration of printing means, and calibration means for correcting deviation in photography characteristics of photographing means and deviation in printing characteristic of printing means. Calibration means drives photographing means to photograph the first test chart, executes calibration of photographing means on the basis of image data of the first test chart, drives photographing means to photograph the second test chart that is printed by driving printing means, and executes calibration of printing means on the basis of image data of the second test chart.
In the preferred embodiment, the apparatus is changeable between a taking mode for photographing and printing a subject, and a calibration mode for carrying out calibration of photographing means and printing means. At least one of photographing means and printing means includes calibration means. The first and second test charts include plural gray patches. Optical densities of these gray patches are different from one another. Guide frames are provided to set the first and second test charts at appropriate positions.
In the taking mode, photographing means executes white balance correction process, flare correction process, and gamma conversion process, and printing means executes gray balance correction process and gradation conversion process. In the calibration mode, calibration means adjusts correction parameters used in white balance correction process, flare correction process, and gamma conversion process. Also, in the calibration mode, calibration means adjusts correction parameters used in gray balance correction process and gradation conversion process.
In an another embodiment, when calibration conditions to carry out calibration are satisfied, a calibration request is sent to a system management computer to urge calibration of the apparatus. Moreover, when a test chart exchange condition to exchange the first and second test charts is satisfied, a test chart exchange request signal is sent to the system management computer. Furthermore, when utilization suspension condition to suspend utilization in said taking mode, a utilization suspension signal is sent to the system management computer, and a message for notifying a user is displayed on a display of the apparatus.
It is possible to carry out calibration by photographing the first and second test charts after printing the second test chart, by executing calibration of photographing means on the basis of image data of the first test chart, and by executing calibration of printing means on the basis of image data of the second test chart.